Carburetor control



May 21, 1940. A. HEEss l-:r Al.

. cARBunEToR coNTnoL Filed Dec. 13. 1938 Patented May 2l, 1940 PATENT OFFICE oAaBUnE'ron CONTROL Albert Heess and Georg Scheerer, Stuttgart-Bad Cannstatt, Germany, assignors to Daimler-Benz Aktiengesellschaft, Stuttgart Unterturkheim,

Germany Application December 13, 1938, Serial No. 245,385 In Germany December 16, 1937 12 claims. (ci.l 12s-119) I This invention relates to an improved carbucally in succession and graduallyv in dependence upon the charging pressureof the blower. This is conveniently accomplished by making use of a piston which is influenced by the blower pressure and is operatively connected with the additional carburetor or carburetors. For the prompt cutting out of additional carburetion upon the sud- A den cutting olf of gas from the main carburetor, the fuel supply of the additional carburetor or carburetors is controlled in dependence upon the operation of the main carburetor throttle. The additional carburetor or carburetors may be cut in and out b'y rotary valve means and may be connected to the float chamber of the main carburetor, each carburetor possessing a separate air suction. All carburetors are disposed in suction passages of the charging blower. v

The foregoing arrangement affords the advan- A tage that the engine gives the best possible output over the whole speed range. The division of the carburetor so that a smaller main carburetor is used in conjunction with one or more additional carburetors ensures good speed transitions and an increased output up to the maximum engine speed. The fact of the additional carburetor or carburetors being cut in gradually and stepwise in dependence upon the pressure of the charging blower delivery, ensures a smooth and jerkless acceleration which is quite independent of the care or skill of the driver.

One practical example of the improved carv buretor control is illustrated in `the annexed supplies the fuel mixture through theV pressure I passage l to the cylinders. The suction passage 7c of the chargingblower i has two lbranches ki and k2, the main carburetor b and throttle e being arranged in the branch k1, and the additional carburetor f, g with its air-suction connection h being in the passage k2. The fuel is conveyed from the tank z through the passage t to the float chamber c, and from the latter passages c1 and c2 lead to the jet b of the main carburetorl and the jet u of the additional carburetor respectively. Thethrottle e of the main carburetor is operated by means of the accelerator pedal and linkage r and also the lever e1. The fuel valve g, which is a needle or cone valve loaded by a spring y, is operated by the pedal and linkage r by way of the lever e2, likewise connected to the throttle e, and the linkage s. As will be seen .from the drawing, the stem of the valve g passes axially through a vertical ported cylinder f which is revoluble in its casing and serves as a valve, the fuel passage c2 also entering this cylindrical body f axially from beneath.

A control piston m is connected to the pressure moved in dependence upon the charging pressurel by the push rod mi acted upon by the piston m, the bell-crank lever p and the linkage q. The bell-crank lever p is limited in its movement by the adjustable stop x. If, for example, two main carburetors are provided each with a float chamber c, then the fuel is supplied to the additional carburetor through the passages c3, c4 or the combined passage c2. In order to avoid an excessive ow of fuel from one :float chamber to the other during the driving round a curve of a vehicle furnished with the arrangement, nonreturn valves v are arranged in the passages c3, c4 which valves, due to centrifugal force, are respectively pressed upon their seatings depending upon whether a right hand or left hand curve is driven round and thus temporarily close the passageca or c4.

The manner of operation of the arrangement isV as follows: With the throttle e only slightly opened, the output of the engine a, and, consequently, the pressure of the charging blower is so low that it cannot overcome the force of the spring o acting upon the piston m and the latter the rotary valve f by way of the linkage mi, p, q, so that the additional carburetor, whose fuel valve g has already been opened previously in dependence upon the movement of the throttle e, gradually comes into operation and brings about a gradual further increase of output of the engine (see Fig. 2). If the throttle e of the main carburetor is suddenly closed, the fuel valve g of the additional carburetor is instantly closed by the linkage e2, s and the said carburetor is put out of action. The rotary valve f, however, closes more slowly in conformity with the decrease of output of the engine and consequent decrease of blower pressure, the force of the spring o then pressing the piston m downwardly.

In place of the single additional carburetorv in the example illustrated, provision may be made of further additional carburetors which are cut in successively and gradually in dependence upon the pressure, increasing with increasing engine output, of the charging blower. Also, in place of one charging blower only, several such blowers may be provided which operate either upon a common pressure passage or upon separate pressure passages.

We claim:

1. In combination, an internal combustion engine, a blower operative for charging said engine, a plurality of carburetors, and a control influenced by charging pressure and operative for successive cut-in of said carburetors.

2. In an internal combustion engine and in combination therewith, a charging blower, a main carburetor and an auxiliary carburetor in the inlet of said blower, a manual control for said carburetors, and automatic control means responsive to, charging pressure and controlling said auxiliary carburetor.

3. In an internal combustion engine and in combination, a charging blower, a main carburetor having a throttle valve and an auxiliary carburetor having a fuel valve and an auxiliary throttle valve in the inlet of said blower, a manual control common to the main throttle and the fuel valve of said auxiliary carburetor, and automatic control means responsive to charging pressure and operative upon an auxiliary throttle in said auxiliary carburetor.

4. In an internal combustion engine having a charging blower and several carburetors, a control arrangement responsive to charging pressure and operative for the cutting in of carburetors in' succession, said control arrangement including a spring-loaded piston having its appropriate face in communication with the blower delivery.

5. In aninternal combustion engine with several carburetors, a throttle for the main carburetor, a fuel control for the remainder of the carburetors, and an operative connection between said throttle and said fuel control, whereby the latter is influenced by the opening or closing of said throttle.

6. In an internal combustion engine with a charging blower and several carburetors, a throttle for the main carburetor, a fuel control for the remainder of the carburetors. an operative connection between said throttle and said fuel control whereby the latter is infiuenced by the opening or closing of said throttle, and pressure sensitive means responsive to charging pressure and operative for cutting individual carburetors in and out in dependence upon charging pressure.

7. In an internal combustion engine with a charging blower and several carburetors, a throttle for one of said carburetors, a valve controlling another carburetor, pressure responsive means influenced by charging pressure and operative upon said valve, fuel supply control means for said other carburetor, and an operative con nection between said throttle and the fuel supply control means of said other carburetor.

8. 1nv an internal combustion engine with a charging blower and main and auxiliary carburetors, a throttle for the main carburetor, a revoluble valve for an auxiliary carburetor, pressure responsive means influenced by charging pressure and operative upon said revoluble valve, a fuel valve for the auxiliary carburetor, and an operative connection between said fuel valve and said throttle.

9. In an internal combustion engine and in combination', a charging blower, a plurality of carburetors, a branched suctionpipe on said blower each branch enclosing one of said carburetors, and pressure responsive means influenced by blower delivery pressure and. operative for cutting in said carburetors in succession.

10. In an internal combustion engine with a charging blower and two carburetors, a common float chamber feeding the two carburetors, and g main and a plurality of additional carburetors, f;

a'throttle flap for controlling the main carburetor, a rotary valve for controlling an addi tional carburetor, a piston subjected on one side to the pressure of the charging blower, spring means acting on said piston oppositely to .s aid 5,

pressure, a push rod on said piston, a bell-crank lever and a rod interconnecting said push rod and the rotary valveA of said additional carburetor for adjusting the same, stop means, acting upon the piston and the bell-crank lever for limiting the movement of the piston in bothdirections, a needle valve for controlling the fuel supply for the additional carburetor, and a linkage connecting the needle valve to the throttle flap, the axis of the spindle of the needle valve 4;,

coinciding with the axis of the rotary valve.

ALBERTHEESS. GEORG SCHEERER. 

